As much as I haven't cared for these as yet, I bought a new one at a garage sale for $25. Guy said he used it once., but it looks unused. No dust in it at all.
I bought mine a couple years ago did all my drills and then put it away haven't needed it again but getting close with a few. Now I just have to figure out how to use it again.
For those who are not tool and die guys, jigs are a reasonable substitute. TonyL shared some additional materials a few months back on tweaking the Drill Doctor.
Have not yet found the magic jig for little bits (under 1/8 inch).
If you sharpen bits daily, it doesn't take long to get the hang of it. But if a person doesn't, the Drill Doctor is for them.
Because I know how, doesn't mean I should recommend for my method to those that don't, therefore I recommend the DD for 99% of those that need a bit to be sharpened.
I bought mine a couple years ago did all my drills and then put it away haven't needed it again but getting close with a few. Now I just have to figure out how to use it again.
I work with a lot of desert ironwood, so mine get sharpened pretty often. Ours is at least twelve years old. It is the original DD 750 Professional. My only complaint is that after you sharpen a brad point bit it isn't a brad point any more!